Ten days after a failed Al-Qa'ida bid to blow up a Northwest flight from Amsterdam to Detroit, US transport officials said the new measures were part of a drive to put in place “long-term, sustainable security measures”.
All passengers flying into the United States from abroad will be subject to random screening or so-called “threat-based” screens, the Transport Security Administration said in a statement.
But it further mandated that “every individual flying into the US from anywhere in the world traveling from or through nations that are state sponsors of terrorism or other countries of interest will be required to go through enhanced screening”.
He boarded the flight at Amsterdam's Schiphol airport after flying in from Lagos, Nigeria.
Cuba, Iran, Sudan and Syria are currently the only four countries deemed by the State Department to be state sponsors of terrorism.
But a senior administration official told the Politico daily that all passengers from other countries of interests “such as Nigeria, Pakistan and Yemen will receive full body pat-down and physical inspection of property”.
“These are changes that weren't widely in place for all carriers or countries on 12/24,” the official told Politico, quoted on its website.
Such screening “could also include explosive detection technology or advanced imaging technology where it's available”.
TSA said the new measures were being introduced “because effective aviation security must begin beyond our borders, and as a result of extraordinary cooperation from our global aviation partners”.
The increased screening came as the United States and Britain closed their embassies in the Yemeni capital Sanaa over security fears, as President Barack Obama's top counter-terrorism advisor warned Al-Qa'ida could be planning another attack.
There were “indications that Al-Qa'ida is planning to carry out an attack against (a) target inside of Sanaa, possibly our embassy,” advisor John Brennan told CNN.
Obama directly linked Al-Qaeda in the Arabian Peninsula (AQAP), a Yemen-based cell of Osama bin Laden's group, to the failed bombing of the Northwest jet carrying 290 people.
He has ordered two reviews into the security lapses which nearly led to another tragedy in a nation still scarred by the Al-Qa'ida attacks of September 11, 2001.
Mr Obama, who is due to end his Christmas vacation in Hawaii today to return to Washington, will huddle with his top security advisors tomorrow to review the findings of the investigations.